1. Field of the Invention
The present generally relates to an energy efficient climate control system for an offshore wind turbine that is integrated with the component cooling system.
2. Related Art
A wind turbine converts the kinetic energy of the wind into electrical energy through its rotor, drivetrain, electrical generator, and converter. An electrical transformer converts the low voltage output from the converter into a high voltage output before the output is sent to a substation at a wind farm. A wind turbine nacelle houses these mechanical and electrical components, namely, the drivetrain, the electrical generator, the converter, and the transformer (which is usually located in the nacelle to reduce power loss due to low voltage electrical transmission). The wind turbine nacelle also houses the components of the hydraulic system needed for blade pitching and nacelle yawing.
These components generate a significant amount of heat while the wind turbine is operating. For their protection and their efficient operation, the heat generated by these components has to be continuously removed. This is typically done by circulating a coolant such as a mixture of ethylene glycol and water through the heat exchangers built into these components. The coolant then transports the heat from these components and dissipates it to the ambient air with the help of air-cooled radiators mounted on the outside of the nacelle. The heat generated by the drivetrain, and that by the hydraulic system, is dissipated to the coolant through liquid-to-liquid heat exchangers in the lubricating oil and the hydraulic fluid sumps, respectively. Thus the wind turbine cooling system helps remove the heat generated by the components in the nacelle.
In addition to dissipating the heat to the coolant, the heat generating components of the wind turbine also dissipate a significant amount of heat from their outer surfaces to the air inside the nacelle. Moreover, the components such as the transformer dissipate the heat primarily to the surrounding air. Therefore, the air inside the nacelle needs to be either continuously replaced by fresh cooler air (an open airflow system) or cooled and re-circulated (a closed airflow system).
In a wind turbine with an open airflow system, the cooler ambient air usually enters through one or more inlets at the nacelle bottom and flows through the nacelle, thus removing heat from the outer surfaces of the heat generating components. The warmer air exits to the outside from the nacelle through one or more outlets at the nacelle top. The fans, typically located either at the inlets or the outlets, and other airflow control devices such as vanes, help regulate the airflow through the nacelle and thus remove the heat from the outer surfaces of the heat generating components.
In a turbine with a closed airflow system, the warmer air from the nacelle is transported to outside the nacelle or to the tower bottom and cooled through an air-to-air heat exchanger or through a chiller, and the cooler air is re-circulated through the nacelle. Fans or blowers and other flow control devices help circulate the airflow through the nacelle. Thus, the wind turbine climate control system helps cool the heat generating components of the turbine from the outside. An open airflow system is typically more economical and simpler to use than a closed airflow system.